Three-layer systems [ferro-super-ferro (FSF)] with very thin insulating junctions between S and both F layers have been prepared. The superconducting transition temperature T_c↑↑ (when both F magnetizations are parallel) is lower than T_c↑↓.
No takes yet. Share an insight, caveat, or question.
Deutscher et al. (1969) studied this question.
Synapse has enriched one closely related paper. Consider it for comparative context: